Jack, as I mentioned to Don, I get NO relay action on ANY relay, as I switch from ANT1 to ANT2 and /or adjust POWER on the K2/KPA100. The KAT100 front panel LEDs light up correctly.
I was almost certain that before when I checked I saw no change on RYDATA, but I checked again and found that RYDATA does indeed switch from steady 5v to steady zero and back, when I switch from ANT1 to ANT2 and back. POWER adjust has no effect on RYDATA. FPDATA is at 5v for for all positions of the K2 panel, although FPDATA briefly drops and returns to 5v when I adjust the K2 and the KAT100 LEDs switch. >>>>> Q3 is probably not your problem. It is an open-drain switch that inverts the 8R signal, conditioning it for the microcontroller. It appears that the MCU provides the pullup for the signal through the internal pullup on PB6. 4.99 volts is about right for this signal. Just what is the "relay problem" you are seeing? If Q3 and the /8R signals were bad, the KAT would not switch to transmit conditions at all. This would be indicated in a number of ways, such as not even trying to tune. Relay troubles, however, could be isolated to a small area in the circuit. _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com